Yes I knew it I knew it I knew it!!!
Humidity!! You have made my day by proving it Athene, Robert!! Thanks so much!!! *runs to measure glass tank*
But seriously I do notice an improvement in my Nep bellii and cuttings when they were last placed in an exoterra terrarium. They sort of root faster and the cut leaves still stay green without wilting. If I can get a bigger tank to accomodate my plants then this will clear my forever infamous issue of low humidity that's been bugging me for ages!!!
By the way, nice design of the terrarium you have there Athene. Ibelieve it is custom made? The handiwork is really neat.